Study On The Delineation Of Urban Development Bounday Under Spatial Constraints And Scale Constraints

National new urbanization plan clearly requires the delineation of urban development boundary,and this boundary has also became a new task of promoting farmland protection and multiple planning integration.In face of the city sprawling and weak limited effect of city expansion,etc.The delineation of urban development boundary not only has guiding significance for arranging all types of land and layout industrial legitimately,but also has practical significance for promoting new urbanization and multiple planning integration.Cellular Automata is a mature model of city land simulation and prediction,promoting CA model by considering the spatial constraints and scale constraints of city development process,the prediction result is more scientific and reasonable.This paper takes Jintan of Jiangsu as study area.Firstly,this paper introduces the growth process and analyzes the characteristics of urban land.Through the methods of variable weight method,fuzzy evaluation method,kernel principal component analysis,determine absolute limit factors,ecological suitability and location suitability of Jintan.Secondly,based on the driving forces and braking forces analysis of urban land scale,predict a reasonable urban land scale of the target year by building a SD model with different scenarios.Finally,combined with spatial constraints and scale constraints,simulate and predict urban land through ArcGIS ModelBuilder model,considering control boundaries of current plannings,delineate the city development boundary.The main research contents and conclusions are as follows:(1)Spatial growth and constraints analysis of urban land:Firstly,analyze urban land from four aspect of growth process,fractal dimension,weight shift and expansion intensity,discover that the expansion trend is to the east direction,then to south,and the expansion rate has slowed down gradually.In addition,through the analysis of ecological suitability and location suitability,discover the areas with high suitability are mainly concentrated near Jincheng,Economiczone and Yaotang,then distribute near each town.(2)Scale analysis and prediction of urban land:Firstly,determine the driving factors(urbanization,economic development,transportation development,industrial zones)and baking factors(ecological security,farmland protection,engineer projection)of urban land scale,then build a SD model and set different target scenarios,determine urban land scale of Jintan in 2020 is 7395.28 hectares by comparing different results under different scenarios.(3)Delineation of urban development bounday:Firstly,simulate urban land of 2012 on the basis of 2004,and compare simulation result with actual situation,the simulation result shows that the main form of urban land is agglomeration effect,but it is difficult to simulate areas with leaping development,overall,the simulation accuracy has achieved desired effect.Then simulate urban land of 2020 on the basis of 2012,simulation result shows that the agglomeration effect is more obvious in the part of city center.In addition,Yaotang shows its expansion trend to the north direction,and its expansion intensity is stronger than other areas.This phenomenon consistents with the current "Jincheng-Economiczone-Yaotang" new group development model.Delineate urban development bounday based on the layout of urban land prediction of Jintan in 2020,then revise the boundary by considering control boundaries of current plannings.Finally,delineate the urban development bounday of Jintan.In conclusion,this paper puts forward a set of methods of delineation of urban development boundary from four aspects:spatial constraints,scale constraints,urban land simulation and prediction,urban development boundary delineation and revision.Improve the spatial constraints and scale constraints of CA model through methods of variable weight,fuzzy evaluation,kernel principal component analysis and system dynamics,the simulation results are more scientific and the urban development boundary is more reasonable.What's more,the urban development boundary can provide references for Jintan in the city planning and construction management in the future.